The distance to the car ahead of me is set to minimum (where the car's rear bumper shows in the settings). Even though the distance is set to minimum, I feel the car leaves a wider gap than it should. Can anyone confirm this ?

The gap doesn't change with speed. I was set to the smallest gap and it maintained it from 70 mph down to 15mph. I am really beginning to like it for heavy traffic situations. Hope you have good luck getting it sorted out.